Propulsion mechanism for motor toboggans



July 6, 1943.

c. J. E. ELIASON 2,323,526

PROPULSION MECHANISM FOR MOTOR TOBOGGANS Filed May 12, 1941 3 Sheets-Sheet l ZEMEes/eAE INVEIiTOR 6342/ J. E. -:4/4.5an/

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named as s, 1943 PROPULSION MECHANISM FOR MOTOR TOBOGGAN S Carl J. E. Eliason. Sayner, Wis.. assiznor to The Four Wheel Drive Auto 00., Clintonville, Wis., a corporation of Wisconsin Application May 12, 1941, Serial No. 393,053

24 Claims.

This invention relates to improvements in propulsion mechanism for motor toboggans of the type disclosed in my former Patent No. 1,650,334. The present application is a companion to an application of Jean R. Shannon for United States Letters Patent on a motor toboggan embodying some of the features hereinafter disclosed.

It is the primary object of the present invention to provide a novel and improved toboggan propulsive mechanism which has excellent traction both in soft snow and on ice, will function substantially without wear, will avoid noise and shock when contacting hard surfaces, and the chains of which will run straight without any tendency to leave the sprockets and without accumulation of ice.

A further object is generally to simplify and improve the construction, arrangement and operation for the purposes mentioned, and still other objects will be apparent from the specification.

In the drawings: i

Fig. i is a view in side elevation of a motor toboggan embodying the improvements I claim.

Fig. 2 is a view of the motor toboggan in plan.

Fig. 3 is anenlarged detail view of the propulsion mechanism partially in side elevation and partially in section.

Fig. 4 is an enlarged detail view of the motor toboggan in cross section on the line 6-4 of" Fig. 1.

Fig. 5 is a fragmentary detail View in plan of the end of the propulsion mechanism shown in Fig. 3.

Fig. 6 is an enlarged fragmentary detail in perspective showing a portion of the propulsion con= veyor and associated track parts.

Fig. 7 is an enlarged detail view in perspective of one of the conveyor cleats shown in a position inverted from the position in which the cleats are illustrated in Fig. 6.

Fig. 8 is an enlarged fragmentary detail view in plan of the interior surface of the propulsion conveyor shown in Fig. 6.

Figs. 9 and 10 are fragmentary details on a greatly enlarged scale of alternative chain and sprocket constructions.

Like parts are identified by the same reference characters throughout the several views.

The device has for its fundamental support a sledge or toboggan structure generically designated by reference character I5. At its forward end the sledge or toboggan structure has at IS a continuous, full-width, toboggan-like portion upwardly curved as shown in Fig. 1. Mounted upon this toboggan-like forward end is the engine I1. Rearwardly of the engine the entire central area of the sledge is open between a pair of laterally spaced ski-like runners l8 and I9 (Fig. 2) which are rearward extensions of the forward toboggan surface It.

The runners it and it are joined in uniformly spaced relation by a series of brackets 2t, 2t, and 22, all of which are made as shown in Fig. e, comprising vertical legs 23 terminating in laterally projecting feet 25 secured to the respective runners i8 and i9 and joined, well above the runners, by a supporting bar 25 upon which the padded seat board Ed is mounted. For reasons explained in the companion application above referred to, the seat board preferably has a rigid connection only with bracket 2E9 and has a sliding connection with the other bracket.

Steering is effected through manipulation of a pair of ski-like runners 3t and 3!, individually pivoted to the forward section it of the supporting sledge by king-pins 32 and ti] respec tively. The runners 3t and 3!! may be held in parallelism by a link it at their forward ends, and they may be steered in any desired manner as by means of the lever 35 connected to kingpin 32 and actuated by link tit from an upright hand lever 36 (Fig. 2).

Power from engine if passes through a trans= mission case 39, preferably containing a reverse gear (not shown). Power output is delivered by sprocket til to a chain ti which drives sprocket 52 on tubular shaft 53 at the forward end of a sub-frame 55 for the propelling mechanism hereinafter to be described. The engine supporting means includes a bracket 56 (Fig. l and Fig. 2).

A pair of links 5?, adjustable as to length for the purpose of tightening chain 55, are pivoted to brackets 56 co-axially with pinion til and pivoted to the sub-frame by means of the pintle bolt 58 upon which the tubular shaft 53 is rotatably mounted. The links 571 transmit the thrust of the propulsion device to the toboggan while permitting the propulsion device in its entirety to have freedom of vertical movement with respect to the toboggan.

The sub-frame 55 is preferably a truss-like structure provided at each side with upper and lower guide members 68 and 66 (Figs. 3 and 4) spaced at suitable intervals by vertical posts 63, 8t and 65. Upper and lower guide members it and 6E are preferably made of wood, but the posts 63, 6d and are made of metal diagonally braced by metal tubes welded thereto as best shown in Figs. 1 and 3.

At the forward end of the sub-frame the driving tubular shaft 53 carries a pair of sprockets Gland 88 over which operate chains 69 and 10 for which sprockets II are rotatably mounted on shaft 12 at the rear of the propulsion subframe 55.

Adjacent the driving sprockets at the forward end of the sub-frame, and also adjacent the idling sprockets at the rear end of the sub-frame, 1

the wooden guide members 88 and 8| are preferably curved toward the axes of the several sprockets as best shown in Fig. 3. While it is dimcult to illustrate on the small scale of the drawings of this application, the lower wooden guide members are preferably not entirely horizontal but curve almost throughout their length so that the front of the track provided for the propelling conveyor is an inch to an inch and a half higher than the lowest point thereof, while the rear end of the track is approximately onequarter inch higher than its lowest point. This arrangement not only makes turning easier, but tends to relieve the sprockets of load, the lower track as a whole being almost throughout its entire length below the level of the front and rear sprockets.

Spanning the space between the guide members in the manner best shown in Figs. 4 and 5, are cleats 15, preferably of the form best illustrated in Figs. 6 and 7. At each end, each cleat has the general form of an angle iron with a normally horizontal flange 18 and a normally vertical flange 11. The horizontal flange has a groove or channel 18 in one face, such face having sliding bearing contact with the wooden guide members 88 and 8| of the sub-frame. In practice the groove or channel 18 will catch snow and pack it to form an icy support upon which the cleat will ride upon the wooden guide surface. I have found that metal to metal contacts for the necessary guiding function are unsuitable and would wear excessively. The same was true of the wooden guide members until I provided the groove or channel. The ice or packed snow which will collect in such a channel will move over the wooden guide surface with practically no wear whatever.

The cleats have ears 18 spaced to receive the respective chains. The space between the chains is spanned by an intermediate portion of each cleat in which the flange 11 of the cleat is displaced to form an apex rearwardly directed with respect to the path of conveyor movement, such apex being designated by reference character 88 in Fig. 6 and Fig. 'I.

At opposite ends of alternate cleats one of the ears 18 is extended to provide a guide shoe 188. The several parts are subject to expansion and contraction in the temperature and moisture conditions to which such machines are subject, and if every cleat had a guide shoe at both of its ends the shoes would tend to become cramped between the guide members 88 and SI, assuming that such guide members were sufficiently close together to be serviceable in confining the path of movement of the cleats and the chains carried thereby. By providing the guide shoes only at alternate ends of successive cleats I am able to give the chains adequate guidance while at the same time preventing any possibilityof cramping action.

Until I developed this means of guiding the they will cut the ice from between successive rollers 88 of the chain 18, or by using sprockets which are considerably under size with respect to the chains as shown at 88 in Fig. 10. In practice I have successfully used a /4 cross section sprocket on a chain.

Held by clamp plate 84 to the inner surfaces of flanges 18 of the successive cleats, is an endless belt 85 having center slack between successive cleats to form deep pockets as indicated at 88, the depth of which should preferably be two or three times the height of the flange portions 11 of the cleats. When the device is operating in soft snow the snow is penetrated not only by the flanges 11 of the cleats, but also by the entir conveyor system to the full depth permitted by the pockets 88 of the belt 85. As a result, considerably increased traction Is afforded and at the same time the propulsion is more efficient, less power being wasted.

As best shown in Fig. 4, there is a guideway between the runners I8 and I8 in which the entire sub-frame and the conveyor system mounted thereon is movabl upwardly and downwardly between the legs 28 of the U-shaped bracket which supports the seat 28. The sub-frame and conveyor system are biased downwardly not only by gravity but by the compression of the springs 81 and 88 which act on rock shafts 88 and 888 respectively, these being provided with suitable bearings on the sub-frame and provided with arms 88 and 8I secured by links 82 to the runners I8 and I8. The downward bias provided by the springs 81 and 88 may be supplemented by manual pressure exerted through a hand lever 85 oscillatable about the axis of'rock shaft 88. As described in the companion application above referred to, the forward or clockwise pressure on hand lever 85 will force downwardly the rear end of the sub-frame 55 while the rearward or counter-clockwise thrust on the lever 25 will push the fore part of the sub-frame downwardly. For reasons more particularly explained in said companion application, it has been found that greatly increased efficiency results from an arrangement in which that end of the sub-frame which is trailing with reference to the direction of movement of the vehicle sustains most of the downward bias, particularly in soft snow.

Where it is desired to coast, it is possible to lift the entire sub-frame. On the under side of the seat 28.are journaled rock shafts 88 and 84 connected by a link 858 and actuated by a hand lever 88 on rock shaft 88. Each of the rock shafts is provided with an arm 81 and the respective arms are connected by the flexible tension elements 88 with the sub-frame, such elements having adequate slack to permit free chains I found considerable difllculty with the downward movement of the sub-frame toward the dotted line position of Fig. 1 for normal propulsion, but nevertheless being so designed that when the lever 88 is pulled counterclockwise about the axis of rock shaft 88, the entire subframe and conveyor system can be lifted clear of the supporting surface, leaving the vehicle free to coast.

Fuel and oil are preferably carried in the tank I88 at the forward end of the'vehicle seat, such tanks being connected by suitable flexible pipes I8I and I82 to the engine. A hand lever I83 is connected by link I84 to the gear shift lever I85 of the engine while the clutch lever I88 of the engine is operated by link I81 from clutch pedal I08. A similar pedal at I88 on the runner I8 operates the throttle lever H8 or other speed in the slmvly lines for fuel and oilfto permit" of relative movement'between' the seat. and this engine, the entire supporting runner structure of the vehicle being preferably highly flexible.

In deep snow it is necessary, or at least desirable, to provide for considerable accuracy of balance, as will .be explained in more detail in the companion application. The center of gravity of the motor I1 is conveniently placed materially to the right of the center line of the toboggan. The center line of the toboggan is indicated at C in Fig. 2, while the center line of the engine is located at D.

In order to equalize or balance the load upon the runners I8 and IS, the seat is disposed materially to the left of the center line or the toboggan, the center line of the seat being indicated at A. The oflset to the left is well illustrated in Fig. 4, where it will be observed that the foot 24 of one of the supporting legs 23 of bracket 20 is so placed as materially to overhang runner l9, whereas the other foot 24 does not so greatly overhang beyond the edge of runner l8. offset of the bracket legs 23 with respect to the runners l8 and 59 brings the propelling conveyor center line to a position where it is slightly oilset from the center line of the toboggan as a whole, as indicated at B. Thecenter line of the seatiseven farther offset, as indicated atA. in Fig. 2.

In normally forward propulsion in soft snow, for which the vehicle is particularly adapted, the propulsion conveyor and sub-frame will normally depend at the approximate angle illustrated in dotted lines in Fig. 2.

The amount of resistance to displacement which is ofiered by snow will be increased according to the amount of snow engaged by the traction surface of the propelling conveyor. Accordingly, the pockets provided by the bagginess of the belt between successive cleats of the conveyor system are of great assistance in increasing propulsive efiort. The device is capable not only of carrying all of the men who are able to ride upon the seat 26, but also capable of towing behind it several heavily loadedtoboggans.

When a. hard surface is encountered by the cleats, I have found that the shock of impact is materially reduced by the wedge-shaped disposition of the flanges '65 at til, impact being further reduced by the fact that the flanges approach an underlying surface gradually after leaving the sprockets. Where the underlying surface is hard it will be found that the wedgeshape of the central portions of the flanges tends to relieve the propelling chains of strain which would be imposed on them if the cleats were straight angle irons. The V-shaped flanges provide, in efiect, a. broad supporting base for each cleat upon which it does not readily tilt in such a way as to stress the chain. Impact shock is further reduced by the fact that the cleats are rigidly supported only at their ends upon the lower wooden guide members 6| which, with the whole sub-frame, are free to yield. While the subframe has considerable'weight and inertia and does not yield readily, the fact that the intervening portions of the flanges T! of the cleats are not directly supported is of great value in reducing shock upon impact with a stone or icy surface, particularly at high speeds.

With the improvements herein described, the

chains are self-clearing and do not accumulate ice. Moreover, theyaresd-guided between the wooden members to and SI that they are no longer dependent upon the sprockets for guidonce, but areheld by the guide members in the proper alignment with the sprockets.

I claim:

1. In a propulsive device, the combination with spaced chains and cleats connecting the chains, of an intervening flexible belt connected with the cleats and comprising an auxiliary supporting surface.

2. The combination of claim 1 in which the belt I is provided with suflicient slack between successive cleats to permit the cleats to penetrate deep- 1y into material traversed thereby, such material being received into the belt slack between cleats.

3. A propulsion system comprising a pair of chains, cleats connected at intervals with the respective chains and projecting at their ends laterally therebeyond, and guide means outside of the respective chains with whichv the projecting ends of said cleats have bearing engagement.

4. The device of claim 3 in which a plurality of cleats have bearing shoes laterally engaged with diiierent guide means.

5. The device of claim 3 in which the surfaces of at least one of said cleats bearing on said guide means are provided with means for holding ice for lubricating the path of travel of the cleat with respect to the guide means.

6. A propulsion device comprising the c mbination with a pair of spaced guide means and two pairs of spaced sprockets therebetween, of chains operating over the sprockets of the respective pairs and adjacent the respective guide means, cleats connected at intervals to both chains and projecting beyond the chains and provided with terminal bearing surfaces ongaging said guide means, guide shoes mounted on the respective cleats singly, each for engagement with one guide means only, and a belt mounted on said cleats and disposed between said chains, said belt having substantial slack between those cleats upon which it is mounted.

7. A propulsion device comprising a sub-frame provided at each side with upper and lower guide means and provided at each end with pairs oi sprockets, of chains operating over the sprockets adjacent the guide means, cleats having bearing contact with the guide means and connected to the respective chains to span the space therebetween, means for propelling said sprockets and chains to propel said cleats, and flanges projecting from the respective cleats and provided with central apices.

8. A propulsion device comprising the combination with a sub-frame provided at its ends with pairs of sprockets and provided at its sides with lower guide means, of chains disposed in spaced relation upon the sprockets of said pairs, cleats connected with the respective chains and having bearing portions engageable with the respective guide means, guide shoes connected with the respective chains to bear alternately against the sides of the respective guide means, said shoes being staggered to avoid cramping said chains between said guide means.

9. A propulsion device comprising the combination with a sub-frame provided at its ends with pairs of sprockets and provided at its sides with lower guide means, of chains disposed in spaced relation upon the sprockets of said pairs, cleats connected with the respective chains and having bearing portions engageable with the respective guide means, guide shoes connected with the respective chains to bear alternately against the sides of the respective guide means, said shoes being staggered to avoid cramping said chains between said guide means, and a belt disposed between said guide means and connected substantially solely with said cleats, said belt having material slack between the cleats to which it is connected, whereby to allow said cleats substantial penetration into an underlying surface.

10. The device of claim 9 in which the por tions of cleats bearing upon said guide means are provided with recesses adapted to entrap compact snow for the lubrication of said cleats in traversing said guide means.

11. A propulsion device comprising the combination with a frame and longitudinally spaced sprockets carried thereby, of chains operating over the respective sprockets, cleats carriedby the chains, and chain guides located at a level to be engaged by said cleats and curved in approaching said sprockets, whereby gradually to pick up hearing contact with said cleats in the operation of said chains.

12. The device of claim 11 in which said cleats have projecting traction flanges obliquely positioned to provide apices rearwardly directed with respect to the direction of chain and cleat travel.

13. A propulsion device comprising the combination with a frame provided with longitudinally spaced pairs of rotors, the rotors of each pair being laterally spaced from each other, of endless conveyors operating over said rotors, cross cleats connecting said conveyors at spaced intervals, and guide means adjacent the paths of the respective conveyors and upon which said cleats have bearing contact, said cleats being free of physical support between said conveyors and guide means.

14. The device of claim 13 in which each cleat has a bearing flange for contact with said guide means and a traction flange projecting substantially at right angles from the bearing flange, said traction flange having an intermediate apex extending across said bearing flange.

15.. The device of claim 13 in which each cleat has a bearing flange for'contact with said guide means and a traction flange projecting substantially at right angles from the bearing flange, said bearing flange having a bearing surface recessed to trap compacted snow and ice for the lubrication of the surfaces of said guide means traversed by said flange.

16. The device of claim 13 in which alternate cleats are provided at opposite ends with bearing shoes laterally engaging the respective guide means.

17.- A propulsion device comprising the combination with a frame provided at longitudinally spaced points with pairs of rotors, the rotors of the respective pairs being laterally spaced from each other, endless conveyors operating over the.

rotors of the respective pairs in laterally spaced relation, cross cleats connected with the respective conveyors at spaced intervals and projecting therebeyond and provided with bearing surfaces, wooden guide members adjacent the paths of the respective conveyors and against which the bearing surfaces of the respective cleats engage, said cleats having channels for the accumulation of compacted snow and ice between said bearing surfaces andsaid guide means for lubrication,

guide shoes connected with opposite ends of a1- temate cleats and engageable laterally with said wooden guide means, traction flanges projecting from the respective cleats and having intermediate apices, and a conveyor belt connected with successive cleats between said first mentioned conveyors and provided with material slack between said cleats, whereby to pocket snow with which said cleats are engaged.

18. In a track type propulsion device, the combination with a propulsion conveyor including tread means and a chain adapted to operate in snow, of a sprocket over which said chain opcrates, said sprocket having teeth of reduced cross section as compared with said chain, whereby to be adapted to eject compacted snow from said chain.

19. In a propulsion device, the combination of a propulsion conveyor comprising tread means and a chain comprising links and cross members and having spaces intervening between the links and successive members, and a sprocket over which said chain operates, said sprocket being provided with wedge-shaped teethreceivable into said spaces and each of wedge-shaped form, whereby to eject compacted snow from said spaces.

20. A propulsion device comprising the combination with a chain and cleats carried thereby, said chain having links and spaced cross members and spaces intervening between the links and cross members, together with a sprocket over which said chain-operates, said sprocket being provided with undersized teeth materially smaller in cross section than said spaces and adapted to enter said spaces to eject packed snow therefrom, and means other than said sprockets for keeping said chain aligned with said sprocket during its operation thereon.

21. In a propulsive device, the combination with a set of spaced conveyor chains and chain propelled tread cleats, of a flexible means constituting an auxiliary supporting surface at a higher level than said cleats, whereby to allow said cleats material penetration into a soft underlying material before said auxiliary supporting surface becomes appreciably effective upon such material, said flexible means being connected for movement with said chains and extending longitudinally therebetween and provided at intervals with slack portions constituting pockets adapted when engaged with soft underlying material to provide increased tractive thrust thereon, supplementing the thrust of said cleats.

22. In a propulsive device, the combination with a sub-frame providing bars, of spaced chains operating in proximity to the respective bars, cleats connecting the chains and propelled thereby beneath the bars in supporting relation thereto, and flexible auxiliary tread means between the bars and connected with the cleats to receive propulsive movement from the chains and to deliver support directly through the cleats to said bars.

23. The structure of claim 22 in which the flexible auxiliary tread means has portions materially above the level of cleats to which it is connected whereby its full supplemental support will not become effective until said cleats have sunk CARL J. E. ELIABON. 

